Breast cancer drug blocked by common antidepressant

February 11th, 2010

A commonly used antidepressant has been found to block the effects of a drug used to treat breast cancer. Doctors have been advised not to prescribe the two drugs together until more information has been found, reports The Guardian.

Being diagnosed with breast cancer is a distressing ordeal and it is no wonder that about a quarter of women with the condition are thought to have depression or anxiety. In these cases many breast cancer patients are prescribed SSRI antidepressants to help them deal with hot flushes, anxiety and other side effects which can be caused by tamoxifen ( a drug routinely used to treat breast cancer).

However, recent developments and studies have found that certain commonly used SSRI antidepressants can interfere with the way tamoxifen works.

The study investigated a group of 2,430 women who took tamoxifen and who also took one of the SSRI antidepressants in question. It followed them up for two and a half years to see what happened to them. Their medical records were then analysed to calculate the effect different amounts of overlap between the two treatments.

The longer the patient took both drugs for the higher the risk of dying from breast cancer.
For every women taking the antidepressant paroxetine for the duration of the time they were also taking tamoxifen, the risk was one additional death for every seven women treated.

If you are currently taking a combination of tamoxifen for breast cancer and an SSRI antidepressant you should make an appointment with your doctor to arrange an alternative. Consult your doctor before you stop taking any medication as stopping suddenly can often case unwanted side effects.